The present invention relates to integrated circuit (IC) testing, and more particularly, to a testing method utilizing at least one signal between ICs (integrated circuits), and ICs and testing systems thereof.
Please refer to FIG. 1. FIG. 1 illustrates a diagram of an IC 20 to be tested by an Automatic Test Equipment (ATE) 10 according to the related art, where the IC 20 is utilized for controlling operations of an electronic device (not shown), such as an optical disc drive. To ensure that the function of IC 20 is correct, it is necessary to perform IC testing of the IC 20, especially in a mass production phase.
As illustrated in FIG. 1, a testing circuit 12 (the shaded portion shown in FIG. 1), usually containing a socket, is utilized for coupling the IC 20 to the ATE 10. When performing IC testing of the IC 20, the ATE 10 sends test signals in the specific input pins of IC 20. According to the received signals from the specific output pins of IC 20, the ATE determines whether the function of IC 20 is correct or not. The conventional testing system based on the ATE 10 is usually expensive that causes the high testing cost of IC 20.
Please refer to FIG. 2. FIG. 2 illustrates a testing system for performing a system level test (SLT) of the IC 20 shown in FIG. 1. The SLT is also known as the on-board test, which means the IC 20 is tested in a test environment that is the same as the actual work environment of the IC 20, such as the optical disc drive mentioned above. As shown in FIG. 2, the testing system comprises a circuit board 30, typically the same as that utilized in the optical disc drive. The circuit board 30 comprises a testing circuit 32 usually containing the socket mentioned above, for coupling the IC 20. The circuit board 30 further comprises a DRAM 34, a FLASH memory 36, and an intermediate circuit 38 for coupling a loader 40 including at least a spindle motor 42 and an optical pickup (OPU) 44. A disc 60 such as a Compact Disc (CD) or a Digital Versatile Disc (DVD), together with a Personal Computer (PC) 80 (which is sometimes replaced by an external controlling circuit) are typically provided to simulate the environment of an end user of the optical disc drive.
During the SLT, the first step is to load the IC 20 in the testing circuit 32. In the second step, the power of the testing system shown in FIG. 2 is turned on, and the initialization of the testing system starts to run. In the coming steps, various functionalities can be tested according to predetermined order. For example, one step is that the PC 80 requests mechanical movements of the loader 40. In another step, the communication between the IC 20 and some of the other components on the circuit board 30 can be verified. Besides, accessing data to/from the disc 60 through the OPU 44 can be further performed. The disadvantage of SLT is large test cost due to the long test time, and the long time is caused by the response time of electronic components, mechanical movements such as those of a disc tray (not shown) driven by the motor 42 and those of the OPU 44, . . . etc., where the mechanical movements especially take considerable time.